Book•
Digital Filters: Analysis and Design
01 Mar 1984-
About: The article was published on 1984-03-01 and is currently open access. It has received 291 citations till now.
Citations
More filters
01 Feb 1986
TL;DR: Wave digital filters (WDFs) as discussed by the authors are modeled after classical filters, preferably in lattice or ladder configurations or generalizations thereof, and have very good properties concerning coefficient accuracy requirements, dynamic range, and especially all aspects of stability under finite-arithmetic conditions.
Abstract: Wave digital filters (WDFs) are modeled after classical filters, preferably in lattice or ladder configurations or generalizations thereof. They have very good properties concerning coefficient accuracy requirements, dynamic range, and especially all aspects of stability under finite-arithmetic conditions. A detailed review of WDF theory is given. For this several goals are set: to offer an introduction for those not familiar with the subject, to stress practical aspects in order to serve as a guide for those wanting to design or apply WDFs, and to give insight into the broad range of aspects of WDF theory and its many relationships with other areas, especially in the signal-processing field. Correspondingly, mathematical analyses are included only if necessary for gaining essential insight, while for all details of more special nature reference is made to existing literature.
937 citations
DOI•
01 Jun 1987TL;DR: In this article, the fundamental conditions required for cancellation are derived in terms of the power spectral densities of the primary and secondary waves, which are in turn related to the geometry-related and source-related parameters of the system.
Abstract: A retrospective review of the development of active noise control systems is presented, arguing that the design of active noise control (ANC) systems should be considered from a control systems point of view. This approach provides a design methodology that accounts for the design parameters of the system which determine its performance, thereby producing an ANC system that reduces the problems associated with, and the limited practical success of, previous techniques. Based on this argument, the fundamental conditions required for cancellation are derived in terms of the power spectral densities of the primary and secondary waves. These conditions are in turn related to the geometry-related (incorporating the acoustic response of the propagation medium) and source-related parameters of the system. From these conditions, the control structures employed in current ANC systems are examined and compared with the reported applications. A method for the design of controllers for use in ANC systems with broadband compact noise sources suitable for implementation on digital signal processing devices is presented. Using this method, experimental results using differing controllers are illustrated and discussed for both synthetic and practical sources. Finally, current developments in ANC systems are summarised and areas for further work are suggested.
599 citations
01 Jul 1985
TL;DR: Stochastic sampling techniques allow the construction of alias-free approximations to continuous functions using discrete calculations and can be applied spatiotemporally as well as to other aspects of scene simulation.
Abstract: Stochastic sampling techniques, in particular Poisson and fittered sampling, are developed and analyzed. These approaches allow the construction of alias-free approximations to continuous functions using discrete calculations. Stochastic sampling scatters high frequency information into broadband noise rather than generating the false patterne produced by regular sampling. The type of randomness used in the sampling process controls the spectral character of the noise. The average sampling rate and the function being sampled determine the amount of noise that is produced. Stochastic sampling is applied adaptively so that a greater number of samples are taken where the function varies most. An estimate is used to determine how many samples to take over a given region. Noise reducing filters are used to increase the efficacy of a given sampling rate. The filter width is adaptively controlled to further improve performance. Stochastic sampling can be applied spatiotemporally as well as to other aspects of scene simulation. Ray tracing is one example of an image synthesis approach that can be antialiased by stochastic sampling.
445 citations
TL;DR: Fractional order differentiators and integrators of order 12 and 14 are designed and implemented in real time using TMS320C6713 DSP processor and tested using National instruments education laboratory virtual instrumentation system (NIELVIS).
Abstract: Studies on analysis, design and applications of analog and digital differentiators and integrators of fractional order is the main objective of this paper. Time and frequency domain analysis, different ways of realization of fractance device is presented. Active and passive realization of fractance device of order 12 using continued fraction expansion is carried out. Later, time and frequency domain analysis of fractance based circuits is considered. The variations of rise time, peak time, settling time, time constant, percent overshoot with respect to fractional order @a is presented. Digital differentiators and integrators of fractional order can be obtained by using direct and indirect discretization techniques. The s to z transforms used for this purpose are revisited. In this paper by using indirect discretization technique fractional order differentiators and integrators of order 12 and 14 are designed. These digital differentiators and integrators are implemented in real time using TMS320C6713 DSP processor and tested using National instruments education laboratory virtual instrumentation system (NIELVIS). The designed fractional order differentiators have been used for the detection of QRS sequences as well as the occurrence of Sino Atrial Rhythms in an ECG signal and also for the detection of edges in an image. The obtained results are in comparison with the conventional techniques.
392 citations
TL;DR: In this article, a new method of designing linear-phase FIR filters is proposed by minimizing a quadratic measure of the error in the passband and stopband, based on the computation of an eigenvector of an appropriate real, symmetric, and positive-definite matrix.
Abstract: A new method of designing linear-phase FIR filters is proposed by minimizing a quadratic measure of the error in the passband and stopband. The method is based on the computation of an eigenvector of an appropriate real, symmetric, and positive-definite matrix. The proposed design procedure is general enough to incorporate both time- and frequency-domain constraints. For example, Nyquist filters can be easily designed using this approach. The design time for the new method is comparable to that of Remez exchange techniques. The passband and stopband errors in the frequency domain can be made equiripple by an iterative process, which involves feeding back the approximation error at each iteration. Several numerical design examples and comparisons to existing methods are presented, which demonstrate the usefulness of the present approach.
357 citations